Welcome to Concrete Boom Pumping 101 – class is now in session.

This equipment overview – and accompanying discussion of the human and site factors that bear heavily on performance and safety – is designed to help contractors increase their familiarity with what’s happening on their jobsites when a concrete pump with boom is at work.

You’ll leave with a basic understanding of concrete boom pump features and how they benefit different applications, whether you’re a “renter” of pumping services or a prospective pump buyer whose annual subcontracting costs are moving you to consider ownership. It’s unquestionably a significant investment that generally ranges from the low hundred-thousands to north of $1 million, so taking time to sort your priorities and preparing questions to ask manufacturers and peers is well worth your time.

Besides its definition in equipment vernacular as an extending “pole,” if you will, the word “boom” used as big noise and big prosperity also applies. Using a boom to pump concrete replaces labor-intensive crane-and-bucket methodology and has brought a loud and lucrative productivity into the business of building everything from bridge decks, home foundations, high rises, and commercial buildings to parking lots and garages, swimming pools, and more.

For the sake of clarity, before we open the proverbial textbook, a word about “renting” in the context of concrete pumping: Unlike the rental of earthmoving construction equipment, the rental of boom pumps is synonymous with subcontracting. Renting a boom pump is almost always joined at the hip with renting the operator; rarely would (or should) a boom pump be rented and operated by a contractor’s personnel. The complexity of the equipment dictates highly trained, highly skilled operators, and no one without American Concrete Pumping Association (ACPA) should ever be at the controls.

Your Jobsite – Act 1, Scene 1

To set the stage of a typical urban jobsite, meet Eric Lindquist, president of 80-year-old family concrete pumping business Adjustable Forms in the Chicago suburb of Lombard. The company works almost exclusively in downtown Chicago on high-rises, and four to six simultaneous jobs is their sweet spot. Logistics, Lindquist says, is one of their top challenges.

Picture the scene: Tight, highly confined building sites with severely restricted access makes staging ready-mix trucks a choreographic feat. Couple that with constant vehicle, pedestrian and bicycle traffic, and you’ve got a jobsite peppered with pressure.

Now add several tons of pumping boom equipment to the mix and you’ve got yourself a pretty intense drama.

And the nature of concrete itself really pours on the pressure.

Adjustable Forms used Schwing America’s SPB 35 boom to pour floors for Essex on the Park in downtown Chicago.
Adjustable Forms Adjustable Forms used Schwing America’s SPB 35 boom to pour floors for Essex on the Park in downtown Chicago.
On the ground, a Schwing SP9500 concrete pump provides the muscle that sends concrete to the boom, however high it needs to go.
Adjustable Forms On the ground, a Schwing SP9500 concrete pump provides the muscle that sends concrete to the boom, however high it needs to go.

“Concrete is one of heaviest building materials that exists and it’s very caustic,” says Tom O’Malley, senior vice president of sales and marketing for Schwing America Inc. in St. Paul, Minn. “It’s a time bomb, too, because it’s an extremely perishable product – and we literally shove this material through a 5-inch pipe to get it where it needs to be. It’s high pressure, high energy consumption, and a high risk.”

Not only that, but jobsite attitudes toward pumping have in some cases taken a turn for the worse, adding more stress to an already difficult plot.

“People sometimes look at it as a ‘hurry-up’ tool,” says Eric Wright, concrete technology product manager for Liebherr USA Co. in Newport News, Va. “I’ve seen situations where the boom truck pulls up and they say, ‘Just go set up over there in the mud and be ready in 45 minutes’ while the crane gets a day to set up. The pump is just as sophisticated and needs just as much stability on the ground. You have lots of people working under the boom just like a crane.”

Pumping With Reach – Your Options

With all that tense and buzzing jobsite activity as a backdrop, let’s move in closer for some machinery details.

When the pour site is high above ground, high with low overhead areas, crowded, environmentally sensitive, or just plain hard to get close to, you’ve got a couple of choices as you consider pumping concrete with boom equipment.

Truck-mounted boom pumps. The vast majority of concrete pumped in the U.S. is pumped by this style. You’ll get an approximate range of reach from under 20 meters to as high as 70 meters. Because boom pumps originated in Europe, they’re specified in metric terms; 1 meter equals a little more than 3 feet, so you achieve more than 200 feet of reach with a 65-meter boom, for example.

The truck and boom together are a formidable weight, to the tune of 30 tons in some cases, so expect to pay sizeable DOT permitting fees. Frost laws in the coldest states limit pounds per axel to as low as five tons, so owners sometimes have to get creative with adding extra axels to comply with these restrictions.

Placing boom with a stationary pump. Challenged by a multistory high-rise that’s growing taller by the week? Here’s the super hero equipment that literally “flies” to the rescue.

Used almost exclusively in this type of application, a placing boom is whisked high in the air to a tower crane pedestal where it can then reach in to pour each subsequent floor level. In this scenario, a large stationary pump on the ground heaves hundreds of truckloads of concrete per day through lines of steel and rubber hose that are snaked up through the elevator shaft, for example. The longest placing booms are in the 39- to 43-meter range.

A placing boom often remains on the jobsite for the duration of the project, which is how Lindquist’s Adjustable Forms company operates. He owns six units, making his fleet of placing booms one of the biggest in Chicago.

Side note: Made by Construction Forms Inc. (Con Forms) in Port Washington, Wis., an alternative product called Spider Placers acts as “an extension cord” to give the pumping job 16 meters to 18 meters (up to 60 feet) of reach; the 18-3 model is a tracked, drivable unit. These, too, must be flown into position with a crane.

Truck-mounted with detachable boom. Combining the advantages of truck-mounted portability and placing booms’ adaptability to rising elevations, some manufacturers offer a detachable boom off the truck – it functions like a placing boom but uses the truck’s pump kit. Detachables account for only about 10% of boom pumping usage in the U.S. That may be due in part to the high cost associated with a specialized feature that’s used only on the largest structures.

It may be a no-brainer, but nonetheless: The bigger the boom, the greater the cost.

But bigger is not always better, despite predominant thinking in our culture, says Wayne Allen, national sales manager at CPE America in Metter, Ga. A smaller boom pump can be a more versatile solution for a wider range of jobs.

“Price goes up for two reasons: the engineering and technology to make that boom length possible, and the cost of the truck that carries the pump,” he says.

Used Market Thoughts

If you’re considering used equipment, know that higher end, high-quality units hold their value very well. Some companies, including Adjustable Forms in Chicago, turn their fleet while it’s still young and well before some would deem necessary. Therefore, good used machines are out there.

“Of course, the older the machine, the more careful you should be,” cautions Jeff Pool, regional sales representative for DY Concrete Pumps Inc. in Alvarado, Texas. “No. 1 would be seeing the most recent boom inspection report. Then I'd want some type of mechanic’s report – how's the transmission, the gear box, the drive line, the tires. I want to know when the last DOT inspection took place. Finally, how well do you know the seller? I'm the kind of guy you see washing his lawn mower after he mows the lawn – that’s the guy I want to buy a pump from.”

The Human Equation
The operator is one of, if not the most, important factors to consider. When the equipment arrives on your job, it’s the most dangerous time of day, says ACPA Executive Director Christi Collins. Certification is mandated by the American Society of Mechanical Engineers and ACPA is the only third party that can provide written assessment and certification, which is required by many public project owners.

“Make sure you have an operator who is familiar with that equipment and has been safety trained,” Collins says. “A really good, trained operator who’s in command of the pour can be the contractor’s best friend.”

And experience cannot be artificially expedited. In other words, an operator who knows how to set up and operate smaller booms cannot be instantly graduated to the 50-plus-meter classes overnight.

Better Safe than Dead
If that sounds severe, then mission accomplished. Gaze for a moment at the most common, and often fatal, hazards:

  • Hose whipping, caused by improper affixing of metal devices at the end of the pump’s flexible hose outlet to control flow. If air builds up, causing the hose to literally whip out of control, a blow to the head can be deadly.
  • Operator distraction – e.g. cell phone usage while pumping.
  • Hitting overhead power lines. You put lives in jeopardy if you go against the operator’s advice to set up away from overhead obstructions.
  • Tipping of the machine due to poor jobsite evaluation and improper outrigger stabilizing.
Darting up and dipping low, Schwing America’s truck-mounted, five-section Champion 38 SX has a unique folding configuration that incorporates roll-and-fold set-up and also features one-sided outrigging.
Schwing America Inc. Darting up and dipping low, Schwing America’s truck-mounted, five-section Champion 38 SX has a unique folding configuration that incorporates roll-and-fold set-up and also features one-sided outrigging.

For obviously good reasons, manufacturers build in safety features. Be certain to check for:

  • Emergency electrical shutoffs (E-stops).
  • One-side support allows the operator to set up outriggers on just one side of the pump truck in very confined workspaces. The machine will determine the safe range for the boom’s movement and, if crossed, an alarm will sound followed by shutdown if the operator continues to cross out of the safe parameter.
  • Hopper grate switch disables the machine when grate is opened.
  • Boom tip shut-off valve prevents hose whipping. (see Con Forms video)

Get The Right Features for Your Application

Reach. A top priority is the reach of the pump’s boom. But before you rush to bring out a 39-meter or larger, make the outrigger spread or footprint an equally high consideration. Every manufacturer has working range drawings, most likely available on their websites.

Donco 3, a woman-owned concrete construction company near Springfield, Mo., shows off the articulation ability of Liebherr’s multifold, five-section boom.
Liebherr Concrete Technology and Donco 3 Donco 3, a woman-owned concrete construction company near Springfield, Mo., shows off the articulation ability of Liebherr’s multifold, five-section boom.

Folding configurations. What you choose all comes down to geography. Here’s a simplistic summary of sources’ explanations:

  • Roll-and-fold is ideal for wide, open spaces with no overhead obstructions because, generally speaking, that’s what you’ll need to unfold this boom. The sections fold under one another in a wide curling fashion and, while unfolding, roll out toward the pour.
  • Z and Double Zs work like an accordion. They go up and into tight openings like windows or up and then lower, like over water and then under a viaduct.
  • RZ, also known as multifold, is a combination of roll-and-fold and Z.

With all three options, the popular pumping style called A-framing is doable – extending two sections up and sections three and four down, for example.

Remote controls. All buttons and joysticks are pretty universal, so operators will find the same functionality from brand to brand.

Handling different mixes. Concrete composition is a necessary discussion between pumping contractor and ready-mix producer well ahead of time. Geography plays a big role in the raw material used in the mix and how much pressure it’ll require.

“Harsh limestone, gap graded sand are common issues with mixes that are difficult to pump,” says O’Malley. “Lightweight concrete can present difficulties, too, as the lightweight aggregate can absorb moisture while pumping.”

Weight. The heavier the equipment, the higher the permitting costs. Manufacturers are trying to help by reducing machine weight without compromising reach, performance, and structural integrity.

However, Liebherr’s Wright considers this an understandable but questionable response. Taking away metal to make a lighter boom pump is a safety issue that potentially threatens the equipment’s structural integrity.

“A pump is sitting there shoving rock through pipe and it’s a very violent action – and the boom is taking all those shocks and everything as it’s moving through,” says Wright. “It takes its toll.”He thinks manufacturers should make the machine what it needs to be rather than being influenced by a market trying to avoid states’ weight-driven revenue mechanisms – which he says do not apply to cranes.

Technology. Computer brains are now included in some brands that, much like your automobile, assist with diagnostic troubleshooting. But there are polar-opposite preferences about how much of this is desired by end users, so the amount of electronic sophistication varies among the brands.

Bottom line: Concrete wants to harden and doesn’t care if your pump is having a failure. When the operator needs a quick fix, consider what his comfort level will be with more or less computerization.

What to Know About Maintenance

The pummeling boom pumps endure points to the obvious realization this equipment needs regular, meticulous maintenance regardless of which end of the price and features spectrum it’s on. If you can’t find time to change the oil, you’ll have plenty of time on your hands when the pump needs a new engine.

Because boom pumps are sold from the factory as opposed to dealerships, equipment owners do most of their own maintenance and service. Help from the manufacturer should be just a phone call away, and you’ll want some assurance about where their traveling mechanics are based, as well as the speed with which the company will get you any parts you need. Be sure to identify who your local trained technicians are if you don’t have one on the payroll.

Here’s what sources recommend to extend machine life:

  • Weekly greasing by hand instead of an auto-greaser gives you the chance to discover problems before they turn catastrophic.
  • Stock common wear parts – pipe, elbows, pistons, various moveable parts in the hopper.
  • Operators who force sharper, rougher mix too quickly wear out pipes, parts, and pieces faster.

Lots of things to consider when choosing the best boom pump unit for the application. Adjustable Forms’ Lindquist made it clear that having a good relationship with your manufacturer is paramount – and the foundation for that is confidence they’ll be there for you long after the sale.